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发表于 2018-6-11 20:38:02
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这篇文章那个25.5公里写的有问题,还是看看NASA的原文吧。。
https://www.nasa.gov/feature/jpl/small-asteroid-or-comet-visits-from-beyond-the-solar-system
The CNEOS team plotted the object's current trajectory and even looked into its future. A/2017 U1 came from the direction of the constellation Lyra, cruising through interstellar space at a brisk clip of 15.8 miles (25.5 kilometers) per second.
The object approached our solar system from almost directly "above" the ecliptic, the approximate plane in space where the planets and most asteroids orbit the Sun, so it did not have any close encounters with the eight major planets during its plunge toward the Sun. On Sept. 2, the small body crossed under the ecliptic plane just inside of Mercury's orbit and then made its closest approach to the Sun on Sept. 9. Pulled by the Sun's gravity, the object made a hairpin turn under our solar system, passing under Earth's orbit on Oct. 14 at a distance of about 15 million miles (24 million kilometers) -- about 60 times the distance to the Moon. It has now shot back up above the plane of the planets and, travelling at 27 miles per second (44 kilometers per second) with respect to the Sun, the object is speeding toward the constellation Pegasus.
大概就是说飞来的速度是25.5千米每秒,至于具体的位置就不知道了,反正肯定不是黄道面时的速度,估计是进入太阳系的速度吧。。目前它以44千米每秒的速度朝着飞马星座飞走了。
说点自己的理解,说起来确实算个大新闻,一般的天体,比如以前观测的彗星、小行星等,他们机械能都很低,绕着中心天体以椭圆轨道运行,天文学家始终认为会有有很高机械能的星际天体,一般的恒星不能将他们捕获,他们会以双曲线轨道掠过中心天体,从而在星系间穿行。但是宇宙太空旷,这样高能的天体也很少,所以这是第一颗来自太阳系以外的星际天体,有很高的研究价值。对于这类天体,可以有助于人类了解星系的形成。
话说回来这货毕竟来自太阳系以外,没有受到太阳系形成时角动量的影响,他的轨道还是相当的骚气的。。
个人感觉这玩意跟外星人关系不大,但是为啥NASA一副搞大新闻的样呢,因为毕竟混口饭不容易啊。。 |
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